Alkyne benzotriazole derivatives

ABSTRACT

The present invention is directed to alkyne benzotriazole derivatives which are potentiators of metabotropic glutamate receptors, particularly the mGluR2 receptor, and which are useful in the treatment or prevention of neurological and psychiatric disorders associated with glutamate dysfunction and diseases in which metabotropic glutamate receptors are involved. The invention is also directed to pharmaceutical compositions comprising these compounds and the use of these compounds and compositions in the prevention or treatment of such diseases in which metabotropic glutamate receptors are involved.

BACKGROUND OF THE INVENTION

The excitatory amino acid L-glutamate (sometimes referred to herein simply as glutamate) through its many receptors mediates most of the excitatory neurotransmission within the mammalian central nervous system (CNS). The excitatory amino acids, including glutamate, are of great physiological importance, playing a role in a variety of physiological processes, such as long-term potentiation (learning and memory), the development of synaptic plasticity, motor control, respiration, cardiovascular regulation, and sensory perception.

Glutamate acts via at least two distinct classes of receptors. One class is composed of the ionotropic glutamate (iGlu) receptors that act as ligand-gated ionic channels. Via activation of the iGlu receptors, glutamate is thought to regulate fast neuronal transmission within the synapse of two connecting neurons in the CNS. The second general type of receptor is the G-protein or second messenger-linked “metabotropic” glutamate (mGluR) receptor. Both types of receptors appear not only to mediate normal synaptic transmission along excitatory pathways, but also participate in the modification of synaptic connections during development and throughout life. Schoepp, Bockaert, and Sladeczek, Trends in Pharmacol. Sci., 11, 508 (1990); McDonald and Johnson, Brain Research Reviews, 15, 41 (1990).

The present invention relates to potentiators of mGlu receptors, in particular mGluR2 receptors. The mGluR receptors belong to the Type III G-protein coupled receptor (GPCR) superfamily. This superfamily of GPCR's including the calcium-sensing receptors, GABAB receptors and pheromone receptors, which are unique in that they are activated by binding of effectors to the amino-terminus portion of the receptor protein. The mGlu receptors are thought to mediate glutamate's demonstrated ability to modulate intracellular signal transduction pathways. Ozawa, Kamiya and Tsuzuski, Prog. Neurobio., 54, 581 (1998). They have been demonstrated to be localized both pre- and post-synaptically where they can regulate neurotransmitter release, either glutamate or other neurotransmitters, or modify the post-synaptic response of neurotransmitters, respectively.

At present, there are eight distinct mGlu receptors that have been positively identified, cloned, and their sequences reported. These are further subdivided based on their amino acid sequence homology, their ability to affect certain signal transduction mechanisms, and their known pharmacological properties. Ozawa, Kamiya and Tsuzuski, Prog. Neurobio., 54, 581 (1998). For instance, the Group I mGluR receptors, which include the mGluR1 and mGluR5, are known to activate phospholipase C (PLC) via Gαq-proteins thereby resulting in the increased hydrolysis of phosphoinositides and intracellular calcium mobilization. There are several compounds that are reported to activate the Group I mGlu receptors including DHPG, (R/S)-3,5-dihydroxyphenylglycine. Schoepp, Goldworthy, Johnson, Salhoff and Baker, J. Neurochem., 63, 769 (1994); Ito, et al., keurorep., 3, 1013 (1992). The Group II mGlu receptors consist of the two distinct receptors, mGluR2 and mGluR3 receptors. Both have been found to be negatively coupled to adenylate cyclase via activation of Gαi-protein. These receptors can be activated by a selective compound such as 1S,2S,SR,6S-2 aminobicyclo[3.1.0]hexane-2,6-dicarboxylate. Monn, et al., J. Med. Chem., 40, 528 (1997); Schoepp, et al., Neuropharmacol., 36, 1 (1997). This activation leads to inhibition of glutamate release in the synapse (Cartmell et al, J Neurochem 75, 889 (2000)). Similarly, the Group III mGlu receptors, including mGluR4, mGluR6, mGluR7 and mGluR8, are negatively coupled to adenylate cyclase via Gαi and are potently activated by L-AP4 (L-(+)-2-amino-4-phosphonobutyric acid). Schoepp, Neurochem. Int., 24, 439 (1994).

Nonselective mGluR2/mGluR3 receptor agonists (Monn, et al., J. Med. Chem., 43, 4893, (2000)) have shown efficacy in numerous animal models of anxiety and psychosis as well as human clinical trials in schizophrenia patients; Patil et al, Nature Medicine, 13, 1102 (2007). Recent reports indicate that mGluR2 but not the mGluR3 receptor mediates the actions of the dual mGluR2/mGluR3 agonist LY379268 in mouse models predictive of antipsychotic activity. Woolley et al, Psycopharmacology, 196, 431 (2008). Additionally, recent animal studies demonstrate that selective potentiation of the mGluR2 receptor has similar effects to such non-selective agonists (Galici et al, Journal of Pharmacology and Experimental Therapeutics, 315, 1181 (2005)) suggesting an alternative strategy concerning the discovery of selective, positive allosteric modulators (PAMs or allosteric potentiators) of mGluR2 (Johnson et al, J. Med. Chem. 46, 3189, (2003); Pinkerton et al., J. Med. Chem., 47, 4595 (2004). These potentiators act by enabling the receptor to produce an enhanced response to endogenous glutamate. Such allosteric potentiators do not bind at the glutamate binding site also known as the “orthosteric site”, and may benefit by binding to a site other than the highly conserved orthosteric site. A potential advantage to this approach includes the opportunity to have a distinct pharmacological profile by enhancing the activity of the endogenous ligand upon its binding to the orthosteric site. The pharmacological distinctions include the potential for pharmacological specificity between related receptor types that share the same endogenous ligand. In addition, positive allosteric modulators of mGluR2 have been shown to potentiate the response of mGluR2 agonists such as LY379268 (Johnson et. Al. Biochemical Soc. Trans. 32, 881 (2004) and this represents an alternative strategy for treatment using mGluR2 selective PAMs.

It has become increasingly clear that there is a link between modulation of excitatory amino acid receptors, including the glutamatergic system, through changes in glutamate release or alteration in postsynaptic receptor activation, and a variety of neurological and psychiatric disorders. e.g. Monaghan, Bridges and Cotman, Ann. Rev. Pharmacol. Toxicol., 29, 365-402 (1989); Schoepp and Sacann, Neurobio. Aging, 15, 261-263 (1994); Meldrum and Garthwaite, Tr. Pharmacol. Sci., 11, 379-387 (1990). The medical consequences of such glutamate dysfunction make the abatement of these neurological processes an important therapeutic goal.

SUMMARY OF THE INVENTION

The present invention is directed to alkyne benzotriazole derivatives which are potentiators of metabotropic glutamate receptors, particularly the mGluR2 receptor, and which are useful in the treatment or prevention of neurological and psychiatric disorders associated with glutamate dysfunction and diseases in which metabotropic glutamate receptors are involved. The invention is also directed to pharmaceutical compositions comprising these compounds and the use of these compounds and compositions in the prevention or treatment of such diseases in which metabotropic glutamate receptors are involved.

DETAILED DESCRIPTION OF THE INVENTION

The invention encompasses a genus of compounds of Formula I

or a pharmaceutically acceptable salt thereof, wherein:

R¹ is selected from the group consisting of:

(1) C₂₋₈alkyl,

(2) C₂₋₈alkenyl,

(3) C₂₋₈alkynyl,

(4) C₃₋₆cycloalkyl-(CH₂)_(p)—, wherein p is 1, 2, 3 or 4, and

(5) benzyl, wherein groups (1) to (5) above are optionally substituted with 1 to 3 R^(a) groups;

each R^(a) and R² is independently selected from the group consisting of: halo, OH, C₁₋₄alkyl, C₁₋₄alkoxy, CF₃, —OCF₃ and —CN;

Y is selected from the group consisting of: halo, CN, C₁₋₄alkyl, C₂₋₄alkenyl and CH₃—S(O)_(k)—, wherein said C₁₋₄alkyl and C₂₋₄alkenyl are optionally substituted with hydroxy, oxo and one or more fluoro groups as allowed by valence, and k is 0, 1 or 2;

X is selected from the group consisting of:

(1) H;

(2) C₁₋₈alkyl, C₃₋₈cycloalkyl, C₂₋₈alkenyl or C₂₋₈alkynyl, any of which is optionally substituted with up to 4 substituents selected from R³, said C₃₋₈cycloalkyl further optionally substituted with 1 or 2 oxo groups and said C₁₋₈alkyl further optionally substituted with ═N—OH;

(3) phenyl, benzyl, benzoylmethyl, heteroaryl, heteroaryl-CH₂—, heteroaryl-CH₂CH₂— or heteroaryl-CH₂CH₂CH₂—, any of which is optionally substituted with up to 4 substituents selected from R³;

(4) Het, Het-CH₂—, Het-CH₂CH₂— or Het-CH₂CH₂CH₂—, any of which is optionally substituted with up to 4 substituents selected from R³, the Het portions thereof further optionally substituted with 1 or 2 oxo groups;

each R³ is independently selected from the group consisting of: halogen, OH, CN, CF₃, R⁵, OR⁵, SR⁵, SOR⁵, SO₂R⁵, SO₂N(R⁴)₂, COR⁴, CO₂R⁴, CON(R⁴)₂, CON(R⁴)OR⁵, N(R⁴)₂, NO₂, NR⁴COR⁵, NR⁴CO₂R⁵, NR⁴—C₁₋₄alkyl-CO₂R⁵, —C₁₋₄alkyl-N(R⁴)₂, —C₁₋₄-alkyl-NR⁴COR⁵ and —C₁₋₄alkyl-NR⁴CO₂R⁵;

each R⁴ independently represents: (1) H, C₁₋₆alkyl, C₂₋₆alkenyl, C₂₋₆alkynyl, C₃₋₁₀cycloalkyl, C₃₋₁₀cycloalkylC₁₋₄alkyl, C₃₋₁₀cycloalkenyl or C₃₋₁₀cycloalkenylC₁₋₄alkyl, any of which except H optionally bear up to 5 halogen atoms or OH, CN, CF₃ and C₁₋₄alkoxy; (2) phenyl, benzyl or heteroaryl, optionally bridged with a methylene, any of which optionally bear up to 3 substituents independently selected from halogen, OH, oxo, CN, CF₃, C₁₋₄alkyl, C₁₋₄hydroxyalkyl, C₃₋₆cycloalkyl, phenyl, heteroaryl, C₁₋₄alkoxy, acetyl, amino, carbamoyl, CO₂—C₁₋₄alkyl, C₁₋₄alkylamino and di(C₁₋₄alkyl)amino; and (3) Het, optionally bridged with a methylene and said Het optionally bearing up to 3 substituents independently selected from halogen, OH, oxo, CN, CF₃, C₁₋₄alkyl, C₁₋₄hydroxyalkyl, C₃₋₆cycloalkyl, phenyl, heteroaryl, C₁₋₄alkoxy, acetyl, amino, carbamoyl, CO₂—C₁₋₄alkyl, C₁₋₄alkylamino and di(C₁₋₄alkyl)amino;

or when two R⁴ group are attached to the same nitrogen atom, they may be joined together with said nitrogen atom to form a non-aromatic monocyclic, a non-aromatic or partially aromatic bicyclic or a non-aromatic spiro-linked heterocyclic system of up to 12 ring atoms which optionally bears up to 4 substitutents independently selected from halogen, OH, oxo, CN, CF₃, C₁₋₄alkyl, C₃₋₆cycloalkyl, phenyl, heteroaryl, C₁₋₄alkoxy, acetyl, amino, C₁₋₄alkylamino and di(C₁₋₄alkyl)amino;

R⁵ has the same definition as R⁴ except that R⁵ is not H;

each “heteroaryl” independently refers to 5- or 6-membered aromatic monocyclic or 9- or 10-membered aromatic bicyclic ring systems, in which at least one ring atom is selected from N or N-oxide, O and S; and

each “Het” independently refers to nonaromatic or partially aromatic mono- or bicyclic heterocyclic systems of up to 10 ring atoms, in which at least one ring atom is selected from N, O and S, where the sulfur atom may be in the form of the S-oxide or S,S-dioxide.

Within the genus, the invention encompasses a first sub-genus of compounds of Formula I, or a pharmaceutically acceptable salt thereof, wherein R² is not present.

Also within the genus, the invention encompasses a second sub-genus of compounds of Formula I, or a pharmaceutically acceptable salt thereof, wherein R¹ is selected from 2,2-dimethylpropyl, 1,2,2-trimethylpropyl, 4,4,4-trifluorobutyl, cyclopropylmethyl and cyclobutylmethyl. Within the second sub-genus, the invention encompasses a first class of compounds of Formula I, or a pharmaceutically acceptable salt thereof, wherein R¹ is selected from 2,2-dimethylpropyl and cyclopropylmethyl.

Also within the genus, the invention encompasses a third sub-genus of compounds of Formula I, or a pharmaceutically acceptable salt thereof, wherein X is Het, optionally substituted with up to 4 substituents selected from R³ and further optionally substituted with 1 or 2 oxo groups. Within the third sub-genus, the invention encompasses a second class of compounds of Formula I, or a pharmaceutically acceptable salt thereof, wherein X is piperidinyl, optionally substituted with up to 4 substituents selected from R³.

Also within the genus, the invention encompasses a fourth sub-genus of compounds of Formula I, or a pharmaceutically acceptable salt thereof, wherein X is heteroaryl optionally substituted with up to 4 substituents selected from R³. Within the fourth sub-genus, the invention encompasses a third class of compounds of Formula I, or a pharmaceutically acceptable salt thereof, wherein X is pyridinyl, pyrazinyl or pyridazinyl, each optionally substituted with up to 4 substituents selected from R³.

Also within the genus, the invention encompasses a fifth sub-genus of compounds of Formula I, or a pharmaceutically acceptable salt thereof, wherein X is C₁₋₆alkyl or C₂₋₆alkenyl, optionally substituted with hydroxy.

Also within the genus, the invention encompasses a sixth sub-genus of compounds of Formula I, or a pharmaceutically acceptable salt thereof, wherein X is Het, Het-CH₂—, Het-CH₂CH₂— or Het-CH₂CH₂CH₂—, optionally substituted with up to 4 substituents selected from R³, the Het portion thereof further optionally substituted with 1 or 2 oxo groups. Within the sixth sub-genus, the invention encompasses a fourth class of compounds of Formula I, or a pharmaceutically acceptable salt thereof, wherein X is imidazolidin-2,4-dione-CH₂—, imidazolidin-2,4-dione-CH₂CH₂— or imidazolidin-2,4-dione-CH₂CH₂CH₂—, each optionally substituted with 1 to 2 substituents selected from R³.

Also within the genus, the invention encompasses a seventh sub-genus of compounds of Formula I, or a pharmaceutically acceptable salt thereof, wherein X is phenyl optionally substituted with up to 4 substituents selected from R³.

Also within the genus, the invention encompasses a eighth sub-genus of compounds of Formula I, or a pharmaceutically acceptable salt thereof, wherein:

R¹ is selected from 2,2-dimethylpropyl and cyclopropylmethyl;

R² is not present;

Y is Cl, Br or CF₃;

X is selected from the group consisting of:

(1) piperidinyl, optionally substituted with COR⁴, up to 4 halogen atoms and C₁₋₄alkyl, optionally bearing up to 5 halogen atoms;

(2) pyridinyl, pyrazinyl or pyridazinyl, each optionally substituted with up to 4 substituents selected from halogen, methoxy, N(R⁴)₂, COR⁴, CON(R⁴)₂ and C₁₋₄alkyl, optionally substituted with hydroxy;

(3) C₁₋₆alkyl or C₂₋₆alkenyl, optionally substituted with hydroxy;

(4) imidazolidin-2,4-dione-CH₂—, imidazolidin-2,4-dione-CH₂CH₂— or imidazolidin-2,4-dione-CH₂CH₂CH₂—, wherein the imidazolidin-2,4-dione portion is optionally substituted with methyl; and

(5) phenyl, optionally substituted with up to 4 substituents selected from halogen, methoxy, N(R⁴)₂, COR⁴, CON(R⁴)₂ and C₁₋₄alkyl, optionally substituted with hydroxy.

The invention also encompasses a compound selected from the examples that follow, or a pharmaceutically acceptable salt thereof.

The invention also encompasses a pharmaceutical composition comprising a compound of the invention in combination with a pharmaceutically acceptable carrier.

The invention also encompasses a method for treating a neurological or psychiatric disorder associated with glutamate dysfunction in a patient in need thereof comprising administering to the patient a therapeutically effective amount of a compound of the invention. The invention also encompasses this method wherein the neurological or psychiatric disorder associated with glutamate dysfunction is schizophrenia.

R³ may be substituted on benzyl, benzoylmethyl, heteroaryl, heteroaryl-CH₂—, heteroaryl-CH₂CH₂— or heteroaryl-CH₂CH₂CH₂—, Het, Het-CH₂—, Het-CH₂CH₂— or Het-CH₂CH₂CH₂— on the any substitutable positions on the phenyl, heteroaryl, Het or alkyl portions.

“Alkyl”, as well as other groups having the prefix “alk”, such as alkoxy, alkanoyl, means carbon chains which may be linear or branched or combinations thereof. Examples of alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, sec- and tert-butyl, pentyl, hexyl, heptyl, octyl, nonyl, and the like.

For groups with alkyl linking groups indicated such as “—C₁₋₄alkyl-N(R⁴)₂”, “—C₁₋₄alkyl-NR⁴COR⁵” and “—C₁₋₄alkyl-NR⁴CO₂R⁵” the alkyl portion may be linear or branched or combinations thereof.

“Hydroxyalkyl” means alkyl as defined above wherein one or more hydrogen atoms are replaced by hydroxy groups.

“Alkenyl” means carbon chains which contain at least one carbon-carbon double bond, and which may be linear or branched or combinations thereof. Examples of alkenyl include vinyl, allyl, isopropenyl, pentenyl, hexenyl, heptenyl, 1-propenyl, 2-butenyl, 2-methyl-2-butenyl, and the like.

“Alkynyl” means carbon chains which contain at least one carbon-carbon triple bond, and which may be linear or branched or combinations thereof. Examples of alkynyl include ethynyl, propargyl, 3-methyl-1-pentynyl, 2-heptynyl and the like.

“Cycloalkyl” means mono-, bi- or tri-cyclic structures, optionally combined with linear or branched structures, having the indicated number of carbon atoms. Examples of cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, adamantyl, cyclododecylmethyl, 2-ethyl-1-bicyclo[4.4.0]decyl, and the like.

“Cycloalkenyl” means cycloalkyl as defined above having at least one double bond, excluding aromatics.

“Alkoxy” means alkoxy groups of a straight or branched having the indicated number of carbon atoms. C₁₋₆alkoxy, for example, includes methoxy, ethoxy, propoxy, isopropoxy, and the like.

Examples of heteroaryl include pyrrolyl, isoxazolyl, isothiazolyl, pyrazolyl, pyridyl, oxazolyl, oxadiazolyl, thiadiazolyl, thiazolyl, imidazolyl, triazolyl, furanyl, triazinyl, thienyl, pyrimidyl, pyridazinyl, pyrazinyl, benzoxazolyl, benzothiazolyl, benzimidazolyl, benzofuranyl, benzothiophenyl, furo(2,3-b)pyridyl, quinolyl, indolyl, isoquinolyl, and the like.

“Halogen” and “halo” includes fluorine, chlorine, bromine and iodine.

When two R⁴ groups are attached to the same nitrogen atom, they may be joined together with said nitrogen atom to form a non-aromatic monocyclic, a non-aromatic or partially aromatic bicyclic or a non-aromatic spiro-linked heterocyclic system of up to 12 ring atoms, which optionally bears up to 4 substitutents as defined above. Examples include morpholine, 1,1-dioxothiomorpholine and the like.

The compounds of the present invention are potentiators of metabotropic glutamate (mGluR) receptor function, in particular they are potentiators of mGluR2 receptors. That is, the compounds of the present invention do not appear to bind at the glutamate recognition site on the mGluR receptor, but in the presence of glutamate or a glutamate agonist, the compounds of the present invention increase mGluR receptor response. The present potentiators are expected to have their effect at mGluR receptors by virtue of their ability to increase the response of such receptors to glutamate or glutamate agonists, enhancing the function of the receptors. It is recognized that the compounds of the present invention would be expected to increase the effectiveness of glutamate and glutamate agonists of the mGluR2 receptor. Thus, the potentiators of the present invention are expected to be useful in the treatment of various neurological and psychiatric disorders associated with glutamate dysfunction described to be treated herein and others that can be treated by such potentiators as are appreciated by those skilled in the art.

The compounds of the present invention may contain one or more asymmetric centers and can thus occur as racemates and racemic mixtures, single enantiomers, diastereomeric mixtures and individual diastereomers. Additional asymmetric centers may be present depending upon the nature of the various substituents on the molecule. Each such asymmetric center will independently produce two optical isomers and it is intended that all of the possible optical isomers and diastereomers in mixtures and as pure or partially purified compounds are included within the ambit of this invention. Any formulas, structures or names of compounds described in this specification that do not specify a particular stereochemistry are meant to encompass any and all existing isomers as described above and mixtures thereof in any proportion. When stereochemistry is specified, the invention is meant to encompass that particular isomer in substantially pure form or as part of a mixture with other isomers in any proportion.

The independent syntheses of these diastereomers or their chromatographic separations may be achieved as known in the art by appropriate modification of the methodology disclosed herein. Their absolute stereochemistry may be determined by the x-ray crystallography of crystalline products or crystalline intermediates which are derivatized, if necessary, with a reagent containing an asymmetric center of known absolute configuration.

If desired, racemic mixtures of the compounds may be separated so that the individual enantiomers are isolated. The separation can be carried out by methods well known in the art, such as the coupling of a racemic mixture of compounds to an enantiomerically pure compound to form a diastereomeric mixture, followed by separation of the individual diastereomers by standard methods, such as fractional crystallization or chromatography. The coupling reaction is often the formation of salts using an enantiomerically pure acid or base. The diastereomeric derivatives may then be converted to the pure enantiomers by cleavage of the added chiral residue. The racemic mixture of the compounds can also be separated directly by chromatographic methods utilizing chiral stationary phases, which methods are well known in the art.

Alternatively, any enantiomer of a compound may be obtained by stereoselective synthesis using optically pure starting materials or reagents of known configuration by methods well known in the art.

In the compounds of generic Formula I, the atoms may exhibit their natural isotopic abundances, or one or more of the atoms may be artificially enriched in a particular isotope having the same atomic number, but an atomic mass or mass number different from the atomic mass or mass number predominantly found in nature. The present invention is meant to include all suitable isotopic variations of the compounds of generic Formula I. For example, different isotopic forms of hydrogen (H) include protium (¹H) and deuterium (²H). Protium is the predominant hydrogen isotope found in nature. Enriching for deuterium may afford certain therapeutic advantages, such as increasing in vivo half-life or reducing dosage requirements, or may provide a compound useful as a standard for characterization of biological samples. Isotopically-enriched compounds within generic Formula I can be prepared without undue experimentation by conventional techniques well known to those skilled in the art or by processes analogous to those described in the Schemes and Examples herein using appropriate isotopically-enriched reagents and/or intermediates.

The term “pharmaceutically acceptable salts” refers to salts prepared from pharmaceutically acceptable non-toxic bases or acids including inorganic or organic bases and inorganic or organic acids. Salts derived from inorganic bases include aluminum, ammonium, calcium, copper, ferric, ferrous, lithium, magnesium, manganic salts, manganous, potassium, sodium, zinc, and the like. A subgroup is the ammonium, calcium, magnesium, potassium, and sodium salts. Salts in the solid form may exist in more than one crystal structure, and may also be in the form of hydrates. Salts derived from pharmaceutically acceptable organic non-toxic bases include salts of primary, secondary, and tertiary amines, substituted amines including naturally occurring substituted amines, cyclic amines, and basic ion exchange resins, such as arginine, betaine, caffeine, choline, N,N′-dibenzylethylene-diamine, diethylamine, 2-diethylaminoethanol, 2-dimethylaminoethanol, ethanolamine, ethylenediamine, N-ethyl-morpholine, N-ethylpiperidine, glucamine, glucosamine, histidine, hydrabamine, isopropylamine, lysine, methylglucamine, morpholine, piperazine, piperidine, polyamine resins, procaine, purines, theobromine, triethylamine, trimethylamine, tripropylamine, tromethamine, and the like.

When the compound of the present invention is basic, salts may be prepared from pharmaceutically acceptable non-toxic acids, including inorganic and organic acids. Such acids include acetic, benzenesulfonic, benzoic, camphorsulfonic, citric, ethanesulfonic, fumaric, gluconic, glutamic, hydrobromic, hydrochloric, isethionic, lactic, maleic, malic, mandelic, methanesulfonic, mucic, nitric, pamoic, pantothenic, phosphoric, succinic, sulfuric, tartaric, p-toluenesulfonic acid, and the like. A subgroup is citric, hydrobromic, hydrochloric, maleic, phosphoric, sulfuric, fumaric, and tartaric acids. It will be understood that, as used herein, references to the compounds of Formula I are meant to also include a pharmaceutically acceptable salts.

Exemplifying the invention are Examples 1 to 35, described herein. The subject compounds are useful in a method of potentiating metabotropic glutamate receptor activity in a patient such as a mammal in need of such inhibition comprising the administration of an effective amount of the compound. The present invention is directed to the use of the subject compounds disclosed herein as potentiators of metabotropic glutamate receptor activity. In addition to primates, especially humans, a variety of other mammals can be treated according to the method of the present invention.

The present invention is further directed to a method for the manufacture of a medicament for potentiating metabotropic glutamate receptor activity in humans and animals comprising combining a compound of the present invention with a pharmaceutical carrier or diluent.

The subject treated in the present methods is generally a mammal, preferably a human being, male or female, in whom potentiation of metabotropic glutamate receptor activity is desired. The term “therapeutically effective amount” means the amount of the subject compound that will elicit the biological or medical response of a tissue, system, animal or human that is being sought by the researcher, veterinarian, medical doctor or other clinician. It is recognized that one skilled in the art may affect the neurological and psychiatric disorders by treating a patient presently afflicted with the disorders or by prophylactically treating a patient afflicted with the disorders with an effective amount of the compound of the present invention. As used herein, the terms “treatment” and “treating” refer to all processes wherein there may be a slowing, interrupting, arresting, controlling, or stopping of the progression of the neurological and psychiatric disorders described herein, but does not necessarily indicate a total elimination of all disorder symptoms, as well as the prophylactic therapy of the mentioned conditions, particularly in a patient who is predisposed to such disease or disorder.

The term “composition” as used herein is intended to encompass a product comprising the specified ingredients in the specified amounts, as well as any product which results, directly or indirectly, from combination of the specified ingredients in the specified amounts. Such term in relation to pharmaceutical composition, is intended to encompass a product comprising the active ingredient(s), and the inert ingredient(s) that make up the carrier, as well as any product which results, directly or indirectly, from combination, complexation or aggregation of any two or more of the ingredients, or from dissociation of one or more of the ingredients, or from other types of reactions or interactions of one or more of the ingredients. Accordingly, the pharmaceutical compositions of the present invention encompass any composition made by admixing a compound of the present invention and a pharmaceutically acceptable carrier. By “pharmaceutically acceptable” it is meant the carrier, diluent or excipient must be compatible with the other ingredients of the formulation and not deleterious to the recipient thereof.

The terms “administration of” and or “administering a” compound should be understood to mean providing a compound of the invention or a prodrug of a compound of the invention to the individual in need of treatment.

The utility of the compounds in accordance with the present invention as potentiators or agonists of metabotropic glutamate receptor activity, in particular mGluR2 activity, may be demonstrated by methodology known in the art. Potencies are determined as follows. The compounds of the present invention may be tested in a fluorescence laser imaging plate reader (FLIPR) based assay. This assay is a common functional assay to monitor Ca²⁺ mobilization in whole cells expressing recombinant receptor coupled with a promiscuous G-protein. CHO dhfr-cells stably expressing recombinant human mGluR2 and Gα16 loaded with Fluo-4 AM (Invitrogen, Carlsbad Calif.) are treated with varying concentrations of compounds and the Ca²⁺ response is monitored on a FLIPR384 (Molecular Devices, Sunnydale Calif.) for agonist activity. The potentiation response is monitored after a subsequent addition of an EC₂₀ concentration of glutamate (900 nM). The maximum calcium response at each concentration of compound for agonism or potentiation are plotted as dose responses curves fitted with a four parameters logistic equation giving EC₅₀ and Hill coefficient using the iterative non linear curve fitting software program.

The compounds of the present invention may also be tested in a [³⁵S]-GTPγS assay. [³⁵S]-GTPγS binding is a common functional assay to monitor Gαi-coupled receptor in native and recombinant receptor membrane preparation. Membranes from CHO_(dhfr) cells stably expressing recombinant hmGluR2 and Gα16 (25 μg) or HEK293 cells stably expressing recombinant rat mGluR2 (25 μg) are incubated in a 96 well plate for 1 hour in the presence of [³⁵S]-GTPγS (0.05 nM), GDP (5 μM), and varying concentrations of compounds, with (for potentiation) or without (for agonism) a sub-threshold (EC₁₀) concentration of glutamate (1500 nM for hmGluR2 or 750 nM for rat mGluR2). The reaction is stopped by rapid filtration over Unifilter GF/B plate (Packard, Bioscience, Meriden Conn.) using a 96-well cell harvester (Brandel Gaithersburg, Md.). After the addition of Microscint 20 (Packard, Bioscience, Meriden Conn.), the filter plates are counted using a Topcount counter (Packard, Bioscience, Meriden Conn., USA). The agonist or the potentiator curves are fitted with a four parameters logistic equation giving EC₅₀ and Hill coefficient using an iterative non linear curve fitting software program.

In particular, Examples 1 to 35 were tested and demonstrated activity in potentiating the mGluR2 receptor in the FLIPR assay, generally with an EC₅₀ of less than about 10 μM. Compounds within the present invention had activity in potentiating the mGluR2 receptor in the FLIPR and GTPγS assays with an EC₅₀ of less than about 1 μM. Examples Examples 1 to 35 resulted in a minimum 1.8-fold potentiation of glutamate response in the presence of an EC₂₀ concentration of glutamate (900 nM). Such results are indicative of the intrinsic activity of the compounds in use as potentiators of mGluR2 receptor activity.

Representative FLIPR EC₅₀ Values

Ex. EC₅₀ (nM) n 1 100 1 2 2708 1 3 414 1 4 1218 1 5 123 1 6 50 2 7 34 2 8 64 2 9 85 1 10 80 1 11 203 1 12 388 1 13 576 1 14 180 1 15 56 2 16 50 2 17 140 1 18 57 2 19 292 1 20 50 2 21 76 1 22 57 2 23 98 1 24 42 2 25 77 1 26 299 1 27 43 2 28 227 1 29 31 2 30 415 1 31 282 1 32 153 1 33 4.8 2 34 34 2 35 12 2

Metabotropic glutamate receptors including the mGluR2 receptor have been implicated in a wide range of biological functions. This has suggested a potential role for these receptors in a variety of disease processes in humans or other species.

The compounds of the present invention have utility in treating, preventing, ameliorating, controlling or reducing the risk of a variety of neurological and psychiatric disorders associated with glutamate dysfunction, including one or more of the following conditions or diseases: acute neurological and psychiatric disorders such as cerebral deficits subsequent to cardiac bypass surgery and grafting, stroke, cerebral ischemia, spinal cord trauma, head trauma, perinatal hypoxia, cardiac arrest, hypoglycemic neuronal damage, dementia (including AIDS-induced dementia), Alzheimer's disease, Huntington's Chorea, amyotrophic lateral sclerosis, ocular damage, retinopathy, cognitive disorders, idiopathic and drug-induced Parkinson's disease, muscular spasms and disorders associated with muscular spasticity including tremors, epilepsy, convulsions, migraine (including migraine headache), urinary incontinence, substance tolerance, substance withdrawal (including, substances such as opiates, nicotine, tobacco products, alcohol, benzodiazepines, cocaine, sedatives, hypnotics, etc.), psychosis, schizophrenia, anxiety (including generalized anxiety disorder, panic disorder, and obsessive compulsive disorder), mood disorders (including depression, mania, bipolar disorders), trigeminal neuralgia, hearing loss, tinnitus, macular degeneration of the eye, emesis, brain edema, pain (including acute and chronic pain states, severe pain, intractable pain, neuropathic pain, and post-traumatic pain), tardive dyskinesia, sleep disorders (including narcolepsy), autism, autism spectrum disorders, attention deficit/hyperactivity disorder, and conduct disorder.

Of the disorders above, the treatment of migraine, anxiety, schizophrenia, and epilepsy are of particular interest. In an embodiment the present invention provides a method for treating migraine, comprising: administering to a patient in need thereof an effective amount of a compound of formula I. In another embodiment the present invention provides a method for preventing or treating anxiety, comprising: administering to a patient in need thereof an effective amount of a compound of formula I. Particularly anxiety disorders are generalized anxiety disorder, panic disorder, and obsessive compulsive disorder. In another embodiment the present invention provides a method for treating schizophrenia, comprising: administering to a patient in need thereof an effective amount of a compound of formula I. In yet another embodiment the present invention provides a method for treating epilepsy, comprising: administering to a patient in need thereof an effective amount of a compound of formula I.

Of the neurological and psychiatric disorders associated with glutamate dysfunction which are treated according to the present invention, the treatment of migraine, anxiety, schizophrenia, and epilepsy encompass a subgroup of the invention. Particular anxiety disorders are generalized anxiety disorder, panic disorder, and obsessive compulsive disorder.

In an embodiment, the present invention provides a method for the treatment of schizophrenia comprising: administering to a patient in need thereof an effective amount of a compound of formula I or a pharmaceutical composition thereof. In one of the available sources of diagnostic tools, The Merck Manual (2006-2007), schizophrenia is characterized by psychosis (loss of contact with reality), hallucinations (false perceptions), delusions (false beliefs), disorganized speech and behavior, flattened affect (restricted range of emotions), cognitive deficits (impaired reasoning and problem solving), and occupational and social dysfunction. The skilled artisan will recognize that there are alternative nomenclatures, nosologies, and classification systems for neurological and psychiatric disorders, including schizophrenia, and that these systems evolve with medical scientific progress.

Thus, in an embodiment the present invention provides a method for treating migraine, comprising: administering to a patient in need thereof an effective amount of a compound of formula I or a pharmaceutical composition thereof. In one of the available sources of diagnostic tools, Dorland's Medical Dictionary (23′ d Ed., 1982, W. B. Saunders Company, Philadelphia, Pa.), migraine is defined as a symptom complex of periodic headaches, usually temporal and unilateral, often with irritability, nausea, vomiting, constipation or diarrhea, and photophobia. As used herein the term “migraine” includes these periodic headaches, both temporal and unilateral, the associated irritability, nausea, vomiting, constipation or diarrhea, photophobia, and other associated symptoms. The skilled artisan will recognize that there are alternative nomenclatures, nosologies, and classification systems for neurological and psychiatric disorders, including migraine, and that these systems evolve with medical scientific progress.

In another embodiment the present invention provides a method for treating anxiety, comprising: administering to a patient in need thereof an effective amount of a compound of Formula I or a pharmaceutical composition thereof. At present, the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) (1994, American Psychiatric Association, Washington, D.C.), provides a diagnostic tool including anxiety and related disorders. These include: panic disorder with or without agoraphobia, agoraphobia without history of panic disorder, specific phobia, social phobia, obsessive-compulsive disorder, post-traumatic stress disorder, acute stress disorder, generalized anxiety disorder, anxiety disorder due to a general medical condition, substance-induced anxiety disorder and anxiety disorder not otherwise specified. As used herein the term “anxiety” includes treatment of those anxiety disorders and related disorder as described in the DSM-IV. The skilled artisan will recognize that there are alternative nomenclatures, nosologies, and classification systems for neurological and psychiatric disorders, and particular anxiety, and that these systems evolve with medical scientific progress. Thus, the term “anxiety” is intended to include like disorders that are described in other diagnostic sources.

In another embodiment the present invention provides a method for treating depression, comprising: administering to a patient in need thereof an effective amount of a compound of Formula I or a pharmaceutical composition thereof. At present, the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) (1994, American Psychiatric Association, Washington, D.C.), provides a diagnostic tool including depression and related disorders. Depressive disorders include, for example, single episodic or recurrent major depressive disorders, and dysthymic disorders, depressive neurosis, and neurotic depression; melancholic depression including anorexia, weight loss, insomnia and early morning waking, and psychomotor retardation; atypical depression (or reactive depression) including increased appetite, hypersomnia, psychomotor agitation or irritability, anxiety and phobias; seasonal affective disorder; or bipolar disorders or manic depression, for example, bipolar I disorder, bipolar II disorder and cyclothymic disorder. As used herein the term “depression” includes treatment of those depression disorders and related disorder as described in the DSM-IV.

In another embodiment the present invention provides a method for treating epilepsy, comprising: administering to a patient in need thereof an effective amount of a compound of Formula I or a pharmaceutical composition thereof. At present, there are several types and subtypes of seizures associated with epilepsy, including idiopathic, symptomatic, and cryptogenic. These epileptic seizures can be focal (partial) or generalized. They can also be simple or complex. Epilepsy is described in the art, such as Epilepsy: A comprehensive textbook. Ed. by Jerome Engel, Jr. and Timothy A. Pedley. (Lippincott-Raven, Philadelphia, 1997). At present, the International Classification of Diseases, Ninth Revision, (ICD-9) provides a diagnostic tool including epilepsy and related disorders. These include: generalized nonconvulsive epilepsy, generalized convulsive epilepsy, petit mal status epilepticus, grand mal status epilepticus, partial epilepsy with impairment of consciousness, partial epilepsy without impairment of consciousness, infantile spasms, epilepsy partialis continua, other forms of epilepsy, epilepsy, unspecified, NOS. As used herein the term “epilepsy” includes these all types and subtypes. The skilled artisan will recognize that there are alternative nomenclatures, nosologies, and classification systems for neurological and psychiatric disorders, including epilepsy, and that these systems evolve with medical scientific progress.

The subject compounds are further useful in a method for the prevention, treatment, control, amelioration, or reduction of risk of the diseases, disorders and conditions noted herein.

The subject compounds are further useful in a method for the prevention, treatment, control, amelioration, or reduction of risk of the aforementioned diseases, disorders and conditions in combination with other agents, including an mGluR agonist.

The term “potentiated amount” refers to an amount of an mGluR agonist, that is, the dosage of agonist which is effective in treating the neurological and psychiatric disorders described herein when administered in combination with an effective amount of a compound of the present invention. A potentiated amount is expected to be less than the amount that is required to provided the same effect when the mGluR agonist is administered without an effective amount of a compound of the present invention.

A potentiated amount can be readily determined by the attending diagnostician, as one skilled in the art, by the use of conventional techniques and by observing results obtained under analogous circumstances. In determining a potentiated amount, the dose of an mGluR agonist to be administered in combination with a compound of formula I, a number of factors are considered by the attending diagnostician, including, but not limited to: the mGluR agonist selected to be administered, including its potency and selectivity; the compound of formula I to be coadministered; the species of mammal; its size, age, and general health; the specific disorder involved; the degree of involvement or the severity of the disorder; the response of the individual patient; the modes of administration; the bioavailability characteristics of the preparations administered; the dose regimens selected; the use of other concomitant medication; and other relevant circumstances.

A potentiated amount of an mGluR agonist to be administered in combination with an effective amount of a compound of formula I is expected to vary from about 0.1 milligram per kilogram of body weight per day (mg/kg/day) to about 100 mg/kg/day and is expected to be less than the amount that is required to provided the same effect when administered without an effective amount of a compound of formula I. Preferred amounts of a co-administered mGlu agonist are able to be determined by one skilled in the art.

The compounds of the present invention may be used in combination with one or more other drugs in the treatment, prevention, control, amelioration, or reduction of risk of diseases or conditions for which compounds of Formula I or the other drugs may have utility, where the combination of the drugs together are safer or more effective than either drug alone. Such other drug(s) may be administered, by a route and in an amount commonly used therefor, contemporaneously or sequentially with a compound of Formula I. When a compound of Formula I is used contemporaneously with one or more other drugs, a pharmaceutical composition in unit dosage form containing such other drugs and the compound of Formula I is encompassed as an embodiment of the invention. However, the combination therapy may also includes therapies in which the compound of Formula I and one or more other drugs are administered on different overlapping schedules. It is also contemplated that when used in combination with one or more other active ingredients, the compounds of the present invention and the other active ingredients may be used in lower doses than when each is used singly. Accordingly, the pharmaceutical compositions of the present invention include those that contain one or more other active ingredients, in addition to a compound of Formula I.

The above combinations include combinations of a compound of the present invention not only with one other active compound, but also with two or more other active compounds.

Likewise, compounds of the present invention may be used in combination with other drugs that are used in the prevention, treatment, control, amelioration, or reduction of risk of the diseases or conditions for which compounds of the present invention are useful. Such other drugs may be administered, by a route and in an amount commonly used therefor, contemporaneously or sequentially with a compound of the present invention. When a compound of the present invention is used contemporaneously with one or more other drugs, a pharmaceutical composition containing such other drugs in addition to the compound of the present invention is encompassed as part of the invention. Accordingly, the pharmaceutical compositions of the present invention include those that also contain one or more other active ingredients, in addition to a compound of the present invention.

The weight ratio of the compound of the compound of the present invention to the second active ingredient may be varied and will depend upon the effective dose of each ingredient. Generally, an effective dose of each will be used. Thus, for example, when a compound of the present invention is combined with another agent, the weight ratio of the compound of the present invention to the other agent will generally range from about 1000:1 to about 1:1000, preferably about 200:1 to about 1:200. Combinations of a compound of the present invention and other active ingredients will generally also be within the aforementioned range, but in each case, an effective dose of each active ingredient should be used.

In such combinations the compound of the present invention and other active agents may be administered separately or in conjunction. In addition, the administration of one element may be prior to, concurrent to, or subsequent to the administration of other agent(s).

The compounds of the present invention may be administered by oral, parenteral (e.g., intramuscular, intraperitoneal, intravenous, ICV, intracisternal injection or infusion, subcutaneous injection, or implant), by inhalation spray, nasal, vaginal, rectal, sublingual, or topical routes of administration and may be formulated, alone or together, in suitable dosage unit formulations containing conventional non-toxic pharmaceutically acceptable carriers, adjuvants and vehicles appropriate for each route of administration. In addition to the treatment of warm-blooded animals such as mice, rats, horses, cattle, sheep, dogs, cats, monkeys, etc., the compounds of the invention are effective for use in humans.

The pharmaceutical compositions for the administration of the compounds of this invention may conveniently be presented in dosage unit form and may be prepared by any of the methods well known in the art of pharmacy. All methods include the step of bringing the active ingredient into association with the carrier which constitutes one or more accessory ingredients. In general, the pharmaceutical compositions are prepared by uniformly and intimately bringing the active ingredient into association with a liquid carrier or a finely divided solid carrier or both, and then, if necessary, shaping the product into the desired formulation. In the pharmaceutical composition the active object compound is included in an amount sufficient to produce the desired effect upon the process or condition of diseases. As used herein, the term “composition” is intended to encompass a product comprising the specified ingredients in the specified amounts, as well as any product which results, directly or indirectly, from combination of the specified ingredients in the specified amounts.

Pharmaceutical compositions intended for oral use may be prepared according to any method known to the art for the manufacture of pharmaceutical compositions and such compositions may contain one or more agents selected from the group consisting of sweetening agents, flavoring agents, coloring agents and preserving agents in order to provide pharmaceutically elegant and palatable preparations. Tablets contain the active ingredient in admixture with non-toxic pharmaceutically acceptable excipients which are suitable for the manufacture of tablets. These excipients may be for example, inert diluents, such as calcium carbonate, sodium carbonate, lactose, calcium phosphate or sodium phosphate; granulating and disintegrating agents, for example, corn starch, or alginic acid; binding agents, for example starch, gelatin or acacia, and lubricating agents, for example magnesium stearate, stearic acid or talc. The tablets may be uncoated or they may be coated by known techniques to delay disintegration and absorption in the gastrointestinal tract and thereby provide a sustained action over a longer period. Compositions for oral use may also be presented as hard gelatin capsules wherein the active ingredient is mixed with an inert solid diluent, for example, calcium carbonate, calcium phosphate or kaolin, or as soft gelatin capsules wherein the active ingredient is mixed with water or an oil medium, for example peanut oil, liquid paraffin, or olive oil.

Aqueous suspensions contain the active materials in admixture with excipients suitable for the manufacture of aqueous suspensions. Oily suspensions may be formulated by suspending the active ingredient in a suitable oil. Oil-in-water emulsions may also be employed. Dispersible powders and granules suitable for preparation of an aqueous suspension by the addition of water provide the active ingredient in admixture with a dispersing or wetting agent, suspending agent and one or more preservatives.

Pharmaceutical compositions of the present compounds may be in the form of a sterile injectable aqueous or oleagenous suspension. The compounds of the present invention may also be administered in the form of suppositories for rectal administration. For topical use, creams, ointments, jellies, solutions or suspensions, etc., containing the compounds of the present invention may be employed. The compounds of the present invention may also be formulated for administered by inhalation. The compounds of the present invention may also be administered by a transdermal patch by methods known in the art.

The pharmaceutical composition and method of the present invention may further comprise other therapeutically active compounds as noted herein which are usually applied in the treatment of the above mentioned pathological conditions.

In the treatment, prevention, control, amelioration, or reduction of risk of conditions which require potentiation of metabotorpic glutamate receptor activity an appropriate dosage level will generally be about 0.01 to 500 mg per kg patient body weight per day which can be administered in single or multiple doses. Preferably, the dosage level will be about 0.1 to about 250 mg/kg per day; more preferably about 0.5 to about 100 mg/kg per day. A suitable dosage level may be about 0.01 to 250 mg/kg per day, about 0.05 to 100 mg/kg per day, or about 0.1 to 50 mg/kg per day. Within this range the dosage may be 0.05 to 0.5, 0.5 to 5 or 5 to 50 mg/kg per day. For oral administration, the compositions are preferably provided in the form of tablets containing 1.0 to 1000 milligrams of the active ingredient, particularly 1.0, 5.0, 10.0, 15.0. 20.0, 25.0, 50.0, 75.0, 100.0, 150.0, 200.0, 250.0, 300.0, 400.0, 500.0, 600.0, 750.0, 800.0, 900.0, and 1000.0 milligrams of the active ingredient for the symptomatic adjustment of the dosage to the patient to be treated. The compounds may be administered on a regimen of 1 to 4 times per day, preferably once or twice per day.

When treating, preventing, controlling, ameliorating, or reducing the risk of neurological and psychiatric disorders associated with glutamate dysfunction or other diseases for which compounds of the present invention are indicated, generally satisfactory results are obtained when the compounds of the present invention are administered at a daily dosage of from about 0.1 milligram to about 100 milligram per kilogram of animal body weight, preferably given as a single daily dose or in divided doses two to six times a day, or in sustained release form. For most large mammals, the total daily dosage is from about 1.0 milligrams to about 1000 milligrams, preferably from about 1 milligrams to about 50 milligrams. In the case of a 70 kg adult human, the total daily dose will generally be from about 7 milligrams to about 350 milligrams. This dosage regimen may be adjusted to provide the optimal therapeutic response.

It will be understood, however, that the specific dose level and frequency of dosage for any particular patient may be varied and will depend upon a variety of factors including the activity of the specific compound employed, the metabolic stability and length of action of that compound, the age, body weight, general health, sex, diet, mode and time of administration, rate of excretion, drug combination, the severity of the particular condition, and the host undergoing therapy.

Abbreviations used in the description of the chemistry and in the Examples that follow are: Ac₂O (acetic anhydride); AcOH (acetic acid); AEBSF (p-aminoethylbenzenesulfonyl fluoride); Boc (tert-butyl carbamate); (Boc)₂O (di-tert-butyl dicarbonate); BSA (bovine serum albumin); BuLi (n-butyl lithium); CDCl₃ (chloroform-d); CuI (copper iodide); CuSO₄ (copper sulfate); DBU (1,8-diazabicyclo[5.4.0]undec-7-ene); DCE (dichloroethane); DCM (dichloromethane); DEAD (diethyl azodicarboxylate); DIPEA or DIEA (diisopropylethylamine); DMBA (1,3-dimethylbarbituric acid); DMF (N,N-dimethylformamide); DMP (Dess-Martin periodinane); DMSO (dimethyl sulfoxide); DPPA (diphenylphosphoryl azide); DTT (dithiothreitol); EDTA (ethylene-diamine-tetra-acetic acid); EGTA (ethylene-glycol-tetra-acetic acid); Et₂O (diethylether); EtOAc (ethyl acetate); EtOH (ethanol); HOAc (acetic acid); HPLC (high-performance liquid chromatography); HRMS (high resolution mass spectrum); LAH (lithium aluminum hydride); LCMS (liquid chromatograph-mass spectrometer); LHMDS (lithium bis(trimethylsilyl)amide); LRMS (low resolution mass spectrum); mCPBA (3-chloroperoxybenzoic acid); MeOH (methanol); MP-B(CN)H₃ (Macroporous cyanoborohydride); NaHCO₃ (sodium bicarbonate); Na₂SO₄ (sodium sulfate); Na(OAc)₃BH (sodium triacetoxyborohydride); NH₄OAc (ammonium acetate); NBS (N-bromosuccinamide); NFSi (N-fluorobenzenesulfonimide); NMP (1-methyl-2-pyrrolidinone); NMR (nuclear magnetic resonance); PBS (phosphate buffered saline); PCR (polymerase chain reaction); Pd(dppf) ([1,1′-bis(diphenylphosphino)ferrocene] palladium); Pd(Ph₃)₄ (palladium(0) tetrakis-triphenylphosphine); POCl₃ (phosphorous oxychloride); PS-DIEA (polystyrene diisopropylethylamine); PS—PPh₃ (polystyrene-triphenyl phosphine); PTSA (para-toluene sulfonic acid); Pyr (pyridine); Selectfluor (1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate); TBAF (tetrabutylammonium fluoride); t-BuOH (tert-butanol); THF (tetrahydrofuran); Tf (trifluoromethanesulfonyl); TFA (trifluoroacetic acid); and TMSCH₂N₂ (trimethylsilyldiazomethane).

The compounds of this invention may be prepared by employing reactions as shown in the following Examples, in addition to other standard manipulations that are known in the literature or exemplified in the experimental procedures.

Example 1 tert-Butyl 4-{[4-bromo-1-(2,2-dimethylpropyl)-1H-benzotriazol-5-yl]ethynyl}piperidine-1-carboxylate

Scheme for Preparation of Example 1:

Step 1 Preparation of 1-(2,2-dimethylpropyl)-5-nitro-1H-1,2,3-benzotriazole

2-Fluoro-5-nitroaniline (10.22 g, 65.5 mmol, 1.0 equiv.) was dissolved in anhydrous dimethylsulfoxide (100 ml) and treated with neopentylamine (7.71 ml, 65.5 mmol, 1.0 equiv.). The mixture was heated at 120° C. for 2 days, cooled to ambient temperature and treated with acetic acid (25 ml), followed by addition of 0.65 M aqueous solution of sodium nitrite (121 ml, 79 mmol, 1.2 equiv.). After 20 minutes at ambient temperature, the mixture was neutralized to pH 7 with NaOH (1N aqueous) and diluted with water. The mixture was filtered and the solid was collected on top of filter and washed twice with water. The residue was purified via silica gel chromatography (EtOAc/Hexane gradient from 0 to 100%) to provide the titled compound: ¹H NMR (500 MHz, CDCl₃)

9.02 (d, 1H, J=2.0 Hz), 8.40 (dd, 1H, J=9.1, 2.0 Hz), 7.62 (d, 1H, J=9.1 Hz), 4.47 (s, 2H), 1.07 (s, 9H) ppm. LRMS m/z (M+H) 235.1 found, 235.3 required.

Step 2 Preparation of 1-(2,2-dimethylpropyl)-1H-1,2,3-benzotriazol-5-amine

1-(2,2-Dimethylpropyl)-5-nitro-1H-1,2,3-benzotriazole (4.46 g, 19.0 mmol, 1.0 equiv.) was dissolved in ethanol (50 ml), sparged under nitrogen, charged with 10% Pd/C (2.03 g, 1.90 mmol, 0.1 equiv.) and then sparged under hydrogen (1 atm). After stirring at room temperature for 5 hrs, the mixture was filtered through Celite and the residue was washed with MeOH. The filtrate was concentrated in vacuo to provide the titled compound. LRMS m/z (M+H) 205.0 found, 205.3 required.

Step 3 Preparation of 4-bromo-1-(2,2-dimethylpropyl)-1H-1,2,3-benzotriazol-5-amine

1-(2,2-Dimethylpropyl)-1H-1,2,3-benzotriazol-5-amine (3.52 g, 17.2 mmol, 1.0 equiv.) was dissolved in chloroform (172 ml) and treated with pyridinium tribromide (5.51 g, 17.2 mmol, 1.0 equiv.). The mixture was stirred at room temperature until LCMS showed almost only product. The solid was collected on top of filter and washed with hexanes. The solid was dissolved in Et₂O/EtOAc and neutralized with saturated aqueous sodium bicarbonate. The organic layers were separated, dried with magnesium sulfate, filtered and concentrated in vacuo to provide the titled compound as a pale white solid: ¹H NMR (500 MHz, CD₃OD)

7.30 (d, 1H, J=8.8 Hz), 7.07 (sb, 3H), 7.02 (d, 1H, J=8.8 Hz), 4.34 (s, 2H), 1.03 (s, 9H) ppm. LRMS m/z (M+H) 283.0 and 285.0 (intensity ratio ˜1:1) found, 283.1 and 285.1 required.

Step 4 Preparation of 4-bromo-1-(2,2-dimethylpropyl)-5-iodo-1H-1,2,3-benzotriazol-5-amine

A solution of para-toluenesulfonic acid monohydrate (510 mg, 2.68 mmol) in acetonitrile (3.5 mL) was treated with 4-bromo-1-(2,2-dimethylpropyl)-1H-1,2,3-benzotriazol-5-amine (1-5) (253 mg, 0.893 mmol). The resulting suspension was cooled to 10-15° C. and treated with an aqueous solution of sodium nitrite (537 μl, 1.79 mmol) and potassium iodide (536 μl, 2.23 mmol). After 10 minutes, the mixture was warmed to ambient temperature, diluted with water and neutralized with sodium bicarbonate (1 M aqueous) to pH 9-10, followed by treatment of 3 M aqueous solution of sodium bisulfite (6 mL). The precipitate was collected by filtration and washed with cold diethyl ether and hexanes. The residue was purified via silica gel chromatography (ethyl acetate/hexanes gradient), providing the titled compound: ¹H NMR (500 MHz, CDCl₃)

7.86 (d, 1H, J=8.7 Hz), 7.25 (d, 1H, J=9.0 Hz), 4.36 (s, 2H), 1.04 (s, 9H) ppm. LRMS m/z (M+H) 393.8 and 395.8 found, 393.9 and 395.9 required.

Step 5 Preparation of tert-butyl 4-{[4-bromo-1-(2,2-dimethylpropyl)-1H-benzotriazol-5-yl]ethynyl}piperidine-1-carboxylate

A solution of 4-bromo-1-(2,2-dimethylpropyl)-5-iodo-1H-1,2,3-benzotriazol-5-amine (0.098 g, 0.25 mmol), tert-butyl 4-ethynylpiperidine-1-carboxylate (0.078 g, 0.37 mmol), and copper (I) iodide (0.024 g, 0.12 mmol) in DMF (1 mL) and triethylamine (1 mL) was purged subsurface with nitrogen, then heated at 80° C. for 1 h. The mixture was diluted with ethyl acetate and washed with saturated aqueous sodium bicarbonate and brine. The organic extracts were dried with magnesium sulfate, filtered, and concentrated in vacuo. The residue was purified via silica gel chromatography (ethyl acetate/hexanes gradient), providing the titled compound: ¹H-NMR (400 MHz, CDCl₃) δ 7.49 (d, J=8.6 Hz, 1H), 7.37 (d, J=8.6 Hz, 1H), 4.38 (s, 2H), 3.72-3.78 (m, 2H), 3.36-3.41 (m, 2H), 2.93-2.95 (m, 1H), 1.88-1.90 (m, 2H), 1.53-1.56 (m, 2H), 1.53 (s, 9H), 1.03 (s, 9H) ppm; LRMS m/z (M+H) 477.2 [calculated for C₂₃H₃₁BrN₄O₂: 477.4].

The following compounds were prepared according to the general procedure described in Example 1, substituting the appropriate alkyne for tert-butyl 4-ethynylpiperidine-1-carboxylate (Step 5) or substituting cyclopropylmethylamine for neopentylamine (Step 1). The starting materials are either commercially available, known in the literature or may be prepared from commercially available reagents using conventional reactions well known in the art.

Ex. NAME HRMS/LRMS 2

4-bromo-1-(2,2-dimethylpropyl)- 5-(piperidin-4-ylethynyl)-1H- benzotriazole C₁₈H₂₃BrN₄ [M + H] Calc'd 377.2 found 377.2 3

tert-butyl 4-{[4-bromo-1- (cyclopropylmethyl)-1H- benzotriazol-5-yl[ethynyl}-4- fluoropiperidine-1-carboxylate C₂₂H₂₆BrFN₄O Calc'd 477.1 found 477.2 4

4-bromo-1-(cyclopropylmethyl)- 5-[(4-fluoropiperidin-4- yl)ethynyl]-1H-benzotriazole C₁₇H₁₈BrFN₄ Calc'd 377.1 found 377.2 5

4-bromo-1- (2,2-dimethylpropyl)-5-{[1- (2,2,2-trifluoroethyl)piperidin- 4-yl]ethynyl}-1H-benzotriazole C₂₀H₂₄BrF₃N₄ Calc'd 457.1 found 457.1

Example 6 4-Chloro-1-(cyclopropylmethyl)-5-[(4-methylpyridin-3-yl)ethynyl]-1H-benzotriazole

Scheme for the Preparation of Example 6

Step 1 Preparation of N-(cyclopropylmethyl)-4-methoxy-2-nitroaniline

A 5 L vessel was charged 4-methoxy-2-nitroaniline (160 g, 952 mmol) in dichloromethane (2.44 L). The mixture was cooled to 10° C. and cyclopropanecarboxyaldehyde (100 g, 143 mmol) was added in four 25 gram portions. The vessel was charged with acetic acid (300 ml, 523 mmol) via an addition funnel over 20 minutes. After 45 minutes, the vessel was charged with sodium triacetoxyborohydride (444 g, 209 mmol) portionwise. The mixture was warmed to ambient temperature over 4 hours and was stirred for an additional 14 hours. The mixture was treated with saturated aqueous sodium bicarbonate (100 mL) and poured into sodium bicarbonate (4 L) and dichloromethane. The organic extract was concentrated in vacuo, providing the titled compound.

Step 2 Preparation of N′-(cyclopropylmethyl)-4-methoxybenzene-1,2-diamine

N-(Cyclopropylmethyl)-4-methoxy-2-nitroaniline (175 g) was dissolved in ethanol (1750 mL) and was added to a 4.0 L Hast ‘C” Shaker can. The mixture was cooled to 10° C. and treated with 3% Pt/0.6% VG/C, deGussa (4.5 g). The vessel was sparged under nitrogen and then sparged three times with hydrogen at a setting of 40 psi and agitated for 2.5 hours. To a pre-washed solka-flok with ethanol, the mixture was filtered through solka-flok through a sintered glass funnel to have about a ½ inch depth of solka-flok. The solka-flok was then washed with 1 L ethanol and concentrated in vacuo, providing the titled compound.

Step 3 Preparation of 1-(cyclopropylmethyl)-5-methoxy-1H-benzotriazole

N¹-(Cyclopropylmethyl)-4-methoxybenzene-1,2-diamine (10.8 g, 56.2 mmol) was dissolved in ethanol (80 mL) and treated with methanesulfonic acid (3.65 ml, 56.2 mmol) followed by isoamyl nitrite (7.56 ml, 56.2 mmol). The mixture was stirred for 15 minutes, diluted with ethyl acetate (1500 mL) and washed with saturated bicarbonate solution (500 mL×2). The organic extracts were concentrated in vacuo. The residue was purified by silica gel gradient chromatography (5-50% ethyl acetate in heptanes), providing the titled compound as a tan solid.

Step 4 Preparation of 4-chloro-1-(cyclopropylmethyl)-5-methoxy-1H-benzotriazole

1-(Cyclopropylmethyl)-5-methoxy-1H-benzotriazole (10 g, 49 mmol) was dissolved in acetic acid (100 mL), cooled to 0° C. and treated with sulfuryl dichloride (4.8 mL, 59 mmol, 1.2 equiv) over three minutes. The mixture was warmed to ambient temperature over three hours and stirred for an additional 14 hours. The mixture was diluted with ethyl acetate and washed with aqueous saturated sodium bicarbonate. The organic layer was dried with magnesium sulfate, filtered and partially concentrated in vacuo to ˜30 mL, which was then treated with water. The resulting precipitate was filtered, collected and dried in vacuo, providing the titled compound.

Step 5 Preparation of 4-chloro-1-(cyclopropylmethyl)-1H-benzotriazol-5-ol

4-Chloro-1-(cyclopropylmethyl)-5-methoxy-1H-benzotriazole (10.5 g, 44.2 mmol) was dissolved in dichloromethane (200 mL), cooled to 0° C. and treated with boron tribromide (88 mL, 1M dichloromethane solution, 88 mmol, 2 equiv). The ice bath was removed and the mixture was stirred for 4 hours at ambient temperature. The mixture was treated with water (10 mL) and then sodium hydroxide (1N aqueous) until pH>10. After stirring for an additional 30 minutes, ammonium chloride (aqueous saturated) was added until the pH of the mixture was adjusted to pH 6-7. The aqueous mixture was extracted exhaustively with dichloromethane containing 5% methanol. The combined organic extracts were dried with sodium sulfate, filtered and concentrated in vacuo, providing the titled compound as a light brown solid.

Step 6 Preparation of 4-chloro-1-(cyclopropylmethyl)-1H-benzotriazol-5-yl trifluoromethanesulfonate

4-Chloro-1-(cyclopropylmethyl)-1H-benzotriazol-5-ol (2.91 g, 13.0 mmol) was suspended in dichloromethane (40 mL), cooled to 0° C. and treated with N,N-diisopropylethylamine (4.55 mL, 26.0 mmol, 2 equiv). The mixture was treated with trifluoromethanesulfonic anhydride (2.86 mL, 16.9 mmol, 1.3 equiv) and stirred for 30 minutes. The mixture was poured into ammonium chloride (100 mL, aqueous saturated) and extracted with dichloromethane (2×150 mL). The combined organic extracts were dried with sodium sulfate, filtered and concentrated in vacuo. The residue was purified by silica gel gradient chromatography (100:0 to 1:1; hexanes:ethyl acetate), providing the titled compound as a light brown solid.

Step 7 Preparation of 4-chloro-1-(cyclopropylmethyl)-5-[(trimethylsilyl)ethynyl]-1H-benzotriazole

A solution of 4-chloro-1-(cyclopropylmethyl)-1H-benzotriazol-5-yltrifluoromethanesulfonate (1.00 g, 2.81 mmol), trimethylsilylacetylene (1.20 mL, 8.43 mmol), copper (I) iodide (0.27 g, 1.4 mmol) and triethylamine (5.17 mL, 37.1 mmol) in DMF (5.6 mL) was sparged under nitrogen and heated at 90° C. for 6 h. The solution was diluted with EtOAc and washed with saturated aqueous sodium bicarbonate and brine. The organic extracts were dried with magnesium sulfate, filtered, and concentrated in vacuo, providing the titled compound as an orange solid: ¹H-NMR (400 MHz, CDCl₃) δ 7.57 (d, J=8.5 Hz, 1H), 7.40 (d, J=8.5 Hz, 1H), 4.50 (d, J=7.1 Hz, 2H), 1.35-1.42 (m, 1H), 0.65-0.70 (m, 2H), 0.45-0.51 (m, 2H), 0.31 (s, 9H) ppm; LRMS m/z (M+H) 304.2 [calculated for C₁₅H₁₉ClN₃Si: 304.1].

Step 8 Preparation of 4-chloro-1-(cyclopropylmethyl)-5-ethynyl-1H-benzotriazole

A solution of 4-chloro-1-(cyclopropylmethyl)-5-[(trimethylsilyl)ethynyl]-1H-benzotriazole (0.72 g, 2.4 mmol) in MeOH (21 mL) and THF (2.1 mL) was treated with potassium carbonate (0.33 g, 2.4 mmol) and stirred for 18 hours. The mixture was concentrated in vacuo and the residue was dissolved in dichloromethane and washed with brine. The organic extracts were dried with magnesium sulfate, filtered, and concentrated in vacuo. The residue was purified by silica gel gradient chromatography (0-35% EtOAc in hexanes), providing the titled compound as a faint yellow oil: ¹H-NMR (400 MHz, CDCl₃) δ 7.60 (d, J=8.6 Hz, 1H), 7.43 (d, J=8.6 Hz, 1H), 4.52 (d, J=7.1 Hz, 2H), 3.44 (s, 1H), 1.36-1.43 (m, 1H), 0.66-0.71 (m, 2H), 0.48-0.52 (m, 2H) ppm; LRMS m/z (M+H) 234.1 [calculated for C₁₂H₁₁ClN₃: 234.1].

Step 9 Preparation of 4-chloro-1-(cyclopropylmethyl)-5-[(4-methylpyridin-3-yl)ethynyl]-1H-benzotriazole

A solution of 4-chloro-1-(cyclopropylmethyl)-5-ethynyl-1H-benzotriazole (20 mg, 0.086 mmol), 3-bromo-4-methylpyridine (30 mg, 0.17 mmol), copper (I) iodide (5 mg, 0.026 mmol), and triethylamine (156 μL, 1.12 mmol) in DMF (0.54 mL) was sparged under nitrogen and heated at 90° C. for 18 hours. The mixture was treated with Quadrapure TU, stirred for 18 hours and filtered. The filtrated was concentrated in vacuo and the residue was purified by preparative reverse-phase HPLC, providing the titled compound: ¹H-NMR (500 MHz, d⁶-DMSO) δ 8.78 (s, 1H), 8.53 (s, 1H), 8.05 (d, J=8.6 Hz, 1H), 7.85 (d, J=8.6 Hz, 1H), 7.44 (s, 1H), 4.67 (d, J=7.3 Hz, 2H), 2.56 (s, 3H), 1.40 (m, 1H), 0.58 (d, J=7.7 Hz, 2H), 0.50 (d, J=5.0 Hz, 2H) ppm; high resolution mass spectrometry (ES+) m/z 323.1058 [(M+H)⁺; calculated for C₁₈H₁₆ClN₄: 323.1058].

The following compounds were prepared according to the general procedure described in Example 6, substituting the appropriate alkyne for ethynyl(trimethyl)silane (Step 7) or substituting the appropriate aryl bromide or aryl iodide for 3-bromo-4-methylpyridine. The starting materials are either commercially available, known in the literature or may be prepared from commercially available reagents using conventional reactions well known in the art.

Ex. NAME HRMS/LRMS 7

4-chloro-1- (cyclopropylmethyl)- 5-(pyridin-3- ylethynyl)-1H- benzotriazole C₁₇H₁₃ClN₄ Calc'd 309.1 found 309.1 8

4-chloro-1- (cyclopropylmethyl)- 5-(pyridin-4- ylethynyl)-1H- benzotriazole C₁₇H₁₃ClN₄ Calc'd 309.1 found 309.1 9

4-chloro-1- (cyclopropylmethyl)- 5-(pyridin-2- ylethynyl)-1H- benzotriazole C₁₇H₁₃ClN₄ Calc'd 309.1 found 309.1 10

4-chloro-1- (cyclopropylmethyl)- 5-(pyrazin-2- ylethynyl)-1H- benzotriazole C₁₆H₁₂ClN₅ Calc'd 310.1 found 310.1 11

4-chloro-1- (cyclopropylmethyl)- 5-(pyridazin-4- ylethynyl)-1H- benzotriazole C₁₆H₁₂ClN₅ Calc'd 310.1 found 310.1 12

4-[4-chloro-1- (cyclopropylmethyl)- 1H-benzotriazol-5- yl]but-3-yn-1-ol C₁₄H₁₅ClN₃O [M + H] Calc'd 276.1 Found 276.1 13

3-[4-chloro-1- (cyclopropylmethyl)- 1H-benzotriazol-5- yl]prop-2-yn-1-ol C₁₃H₁₃ClN₃O [M + H] Calc'd 262.1 Found 262.1 14

5-[4-chloro-1- (cyclopropylmethyl)- 1H-benzotriazol-5- yl]pent-4-yn-1-ol C₁₅H₁₇ClN₃O [M + H] Calc'd 290.1 found 290.0 15

5-{[4-chloro-1- (cyclopropylmethyl)- 1H-benzotriazol-5- yl]ethynyl}pyridine- 3-carbaldehyde C₁₈H₁₄ClN₄O [M + H] (³⁵Cl) Calc'd 337.1 found 337.1 16

4-chloro-1- (cyclopropylmethyl)- 5-[(2-methylpyridin- 3-yl)ethynyl]-1H- benzotriazole C₁₈H₁₆ClN₄ [M + H] Calc'd 323.1058 found 323.1058 17

4-chloro-1- (cyclopropylmethyl)- 5-[(6-methylpyridin- 3-yl)ethynyl]-1H- benzotriazole C₁₈H₁₆ClN₄ [M + H] Calc'd 323.1058 found 323.1056 18

4-chloro-1- (cyclopropylmethyl)- 5-[(5-methylpyridin- 3-yl)ethynyl]-1H- benzotriazole C₁₈H₁₆ClN₄ [M + H] Calc'd 323.1058 found 323.1061 19

4-chloro-5-[(5- chloropyridin-3- yl)ethynyl]-1- (cyclopropylmethyl)- 1H-benzotriazole C₁₇H₁₃Cl₂N₄ [M + H] Calc'd 343.0512 found 343.0511 20

4-chloro-1- (cyclopropylmethyl)- 5-[(5- methoxypyridin-3- yl)ethynyl]-1H- benzotriazole C₁₈H₁₅ClN₄O [M + H] Calc'd 339.1007 found 339.1010 21

4-chloro-1- (cyclopropylmethyl)- 5-[(5- fluoropyridin-3- yl)ethynyl]-1H- benzotriazole C₁₇H₁₂ClFN₄ [M + H] Calc'd 327.0807 found 327.0808 22

(5-{[4-chloro-1- (cyclopropylmethyl)- 1H-benzotriazol-5- yl]ethynyl}pyridin-3- yl)methanol C₁₈H₁₅ClN₄O [M + H] Calc'd 339.1007 found 339.1010 23

5-{[4-chloro-1- (cyclopropylmethyl)- 1H-benzotriazol-5- yl]ethynyl}pyridin-3- amine C₁₇H₁₄ClN₅ [M + H] Calc'd 324.1011 found 324.1011 24

5-{[4-chloro-1- (cyclopropylmethyl)- 1H-benzotriazol-5- yl]ethynyl}pyridine- 3-carboxamide C₁₈H₁₄ClN₅O [M + H] Calc'd 352.0960 found 352.0960 25

4-chloro-1- (cyclopropylmethyl)- 5-[(2-fluoropyridin- 4-yl)ethynyl]-1H- benzotriazole C₁₇H₁₂ClFN₄ [M + H] Calc'd 327.0807 found 327.0811 26

4-chloro-5-[(2- chloropyridin-4- yl)ethynyl]-1- (cyclopropylmethyl)- 1H-benzotriazole C₁₇H₁₂Cl₂N₄ [M + H] Calc'd 343.0512 found 343.0517 27

4-chloro-1- (cyclopropylmethyl)- 5-[(2-methylpyridin- 4-yl)ethynyl]-1H- benzotriazole C₁₈H₁₅ClN₄ [M + H] Calc'd 323.1058 found 323.1058 28

4-chloro-1- (cyclopropylmethyl)- 5-[(2- methoxypyridin-4- yl)ethynyl]-1H- benzotriazole C₁₈H₁₅ClN₄O [M + H] Calc'd 339.1007 found 339.1010 29

4-{[4-chloro-1- (cyclopropylmethyl)- 1H-benzotriazol-5- yl]ethynyl}pyridin-2- amine C₁₇H₁₄ClN₅ [M + H] Calc'd 324.1011 found 324.1011

Example 30 1-{3-[4-Chloro-1-(cyclopropylmethyl)-1H-benzotriazol-5-yl]prop-2-yn-1-yl}-3-methylimidazolidine-2,4-dione

Scheme for the Preparation of Example 30:

Step 1 Preparation of 3-[4-chloro-1-(cyclopropylmethyl)-1H-benzotriazol-5-yl]prop-2-yn-1-yl methanesulfonate

A 0° C. solution of 3-[4-chloro-1-(cyclopropylmethyl)-1H-benzotriazol-5-yl]prop-2-yn-1-ol [(Example 1, Step 5) 66 mg, 0.252 mmol] in dichloromethane (3 ml) was treated with methanesulfonyl chloride (0.025 ml, 0.315 mmol) and diisopropylethylamine (0.088 ml, 0.504 mmol). After 30 minutes, the mixture was purified by silica gel gradient chromatography (0-5% acetone/dichloromethane), providing the titled compound as a colorless solid. LRMS m/z (M+H) 340.0 found, 340.8 required.

Step 2 Preparation of 1-{3-[4-chloro-1-(cyclopropylmethyl)-1H-benzotriazol-5-yl]prop-2-yn-1-yl}-3-methylimidazolidine-2,4-dione

3-[4-Chloro-1-(cyclopropylmethyl)-1H-benzotriazol-5-yl]prop-2-yn-1-yl methanesulfonate (30 mg, 0.088 mmol), 3-methylimidazolidine-2,4-dione (20.15 mg, 0.177 mmol), and potassium carbonate (36.6 mg, 0.265 mmol) were combined in acetonitrile (1 ml) and heated at 50° C. for 24 hours. The mixture was cooled to ambient temperature, diluted with ethyl acetate and washed with saturated aqueous ammonium chloride and brine. The organic extract was dried with sodium sulfate, filtered, concentrated in vacuo. The residue was purified by silica gel gradient chromatography (0-5% acetone/dichloromethane) to provide the titled compound: ¹H NMR (500 MHz, d⁶-DMSO) δ 7.97 (d, J=8.6 Hz, 1H), 7.73 (d, J=8.6 Hz, 1H), 4.64 (d, J=7.3 Hz, 2H), 4.53 (s, 2H), 4.13 (s, 2H), 2.88 (s, 3H), 1.42-1.34 (m, 1H), 0.56 (m, 2H), 0.47 (m, 2H) ppm. LRMS m/z (M+H) 358.0 [calculated for C₁₇H₁₇ClN₅O₂: 358.8].

The following compounds were prepared according to the general procedure described in Example 30, substituting the appropriate alcohol for 3-[4-chloro-1-(cyclopropylmethyl)-1H-benzotriazol-5-yl]prop-2-yn-1-ol (Step 1). The starting materials are either commercially available, known in the literature or may be prepared from commercially available reagents using conventional reactions well known in the art.

Ex. NAME HRMS/LRMS 31

5-but-3-en-1-yn-1- yl-4-chloro-1- (cyclopropylmethyl)- 1H-benzotriazole C₁₄H₁₃ClN₃ [M + H] Calc'd 258.7 found 258.0 32

1-{5-[4-chloro-1- (cyclopropylmethyl)- 1H-benzotriazol-5- yl]pent-4-yn-1-yl}-3- methylimidazolidine- 2,4-dione C₁₉H₂₁ClN₅O₂ [M + H] Calc'd 386.8 found 385.9

Example 33 1-(Cyclopropylmethyl)-5-(pyridin-3-ylethynyl)-4-(trifluoromethyl)-1H-benzotriazole

Scheme for the Preparation of Example 33:

Step 1 Preparation of 1-(cyclopropylmethyl)-1H-benzotriazol-5-ol

1-(Cyclopropylmethyl)-5-methoxy-1H-benzotriazole (11.0 g, 54.1 mmol) was dissolved in dichloromethane (200 mL) and cooled to 0° C. The mixture was treated with boron tribromide (108 mL, 1 M dichloromethane solution, 108 mmol, 2 equiv) and warmed to ambient temperature. After stirring for 3 hours, the mixture was carefully treated with sodium bicarbonate over 1 hour (˜100 mL, aqueous saturated) and the mixture was stirred for an additional 14 hours. The mixture was neutralized to pH <5 with 12 N aqueous hydrochloric acid dropwise and the mixture was extracted with dichloromethane containing 10% methanol (4×750 mL). The combined organic extracts were dried with sodium sulfate, filtered and concentrated in vacuo, providing the titled compound.

Step 2 Preparation of 1-(cyclopropylmethyl)-4-iodo-1H-benzotriazol-5-ol

1-(Cyclopropylmethyl)-1H-benzotriazol-5-ol (5.41 g, 28.6 mmol) was dissolved in acetic acid (75 mL) and treated with N-iodosuccinimide (4.79 g, 21.3 mmol, 0.74 equiv) portionwise. After 15 minutes, the mixture was diluted with water (150 mL) and extracted with dichloromethane (2×100 mL). The combined organic extracts were dried with sodium sulfate, filtered and concentrated in vacuo, providing the titled compound.

Step 3 Preparation of 5-benzyloxy-1-(cyclopropylmethyl)-4-iodo-1H-benzotriazole

1-(Cyclopropylmethyl)-4-iodo-1H-benzotriazol-5-ol (9.01 g, 28.6 mmol) was suspended in degassed N,N-dimethylformamide (75 mL) and treated with benzylbromide (3.74 mL, 31.5 mmol, 1.1 equiv) and potassium carbonate (19.8 g, 143 mmol, 5 equiv). The mixture was placed into a preheated oil bath at 50° C. for 30 minutes, cooled to ambient temperature and diluted with water (500 mL). The mixture was extracted with dichloromethane (2×500 mL) and the combined organic extracts were dried with sodium sulfate, filtered and concentrated in vacuo, providing the titled compound.

Step 4 Preparation of 5-benzyloxy-4-(cyclopropylmethyl)-4-(trifluoromethyl)-1H-benzotriazole

5-Benzyloxy-1-(cyclopropylmethyl)-4-iodo-1H-benzotriazole (1.29 g, 3.2 mmol), copper(I) iodide (1.21 g, 6.39 mmol, 2 equiv) and methyl 2,2-difluoro-2-(fluorosulfonyl)acetate (1.33 mL, 6.39 mmol, 2 equiv) were combined in degassed N,N-dimethylformamide (25 mL) at ambient temperature and placed into a preheated oil bath at 100° C. for 1.5 hours. The mixture was cooled to ambient temperature, poured into water (200 mL), treated with ethyl acetate (100 mL) and Celite. The mixture was aged for 30 minutes, filtered, and partitioned. The aqueous layer was further extracted with ethyl acetate (2×100 mL) and the combined organic extracts were washed with sodium bicarbonate (100 mL, aqueous saturated) and brine (50 mL), dried with sodium sulfate, filtered and concentrated in vacuo. The residue was purified by silica gel gradient chromatography (100:0 to 25:75; hexanes:ethyl acetate), providing the titled compound as a colorless oil.

Step 5 Preparation of 1-(cyclopropylmethyl)-4-(trifluoromethyl)-1H-benzotriazol-5-ol

5-Benzyloxy-1-(cyclopropylmethyl)-4-(trifluoromethyl)-1H-benzotriazole (5.04 g, 14.5 mmol) was dissolved in 1:1 mixture of methanol: ethyl acetate (40 mL). The mixture was sparged under nitrogen, treated with Pearlman's catalyst (2 g, 0.2 wt equiv) and then sparged under hydrogen (1 atm) and stirred vigorously for 90 minutes. The mixture was filtered through a pad of Celite, which was washed with methanol (500 mL) and concentrated in vacuo, providing the titled compound

Step 6 Preparation of 1-(cyclopropylmethyl)-4-(trifluoromethyl)-1H-benzotriazol-5-yl trifluoromethanesulfonate

1-(Cyclopropylmethyl)-4-(trifluoromethyl)-1H-benzotriazol-5-ol (0.81 g, 3.1 mmol) was suspended in dichloromethane (20 mL) and treated with N,N-diisopropylethylamine (1.6 mL, 9.4 mmol, 3 equiv). The mixture was cooled to 0° C., treated with trifluoromethanesulfonic anhydride (0.80 mL, 4.7 mmol, 1.5 equiv) and stirred for 20 minutes. The mixture was poured into water (50 mL) and extracted with dichloromethane (2×50 mL) and the combined organic extracts were dried with sodium sulfate, filtered and concentrated in vacuo. The residue was purified by silica gel gradient chromatography (100:0 to 0:100; hexanes:ethyl acetate), providing the titled compound as an off white solid.

Step 6 Preparation of 1-(cyclopropylmethyl)-5-(pyridin-3-ylethynyl)-4-(trifluoromethyl)-1H-benzotriazole

1-(Cyclopropylmethyl)-4-(trifluoromethyl)-1H-benzotriazol-5-yl trifluoromethanesulfonate (25 mg, 0.064 mmol), 3-ethynylpyridine (13.3 mg, 0.128 mmol), triethylamine (116 μL, 0.835 mmol), tetra-n-butyl ammonium iodide (0.1 equiv), and copper (I) iodide (4 mg, 0.019 mmol) were combined in DMF (0.64 mL) and the mixture was sparged under nitrogen. Tetrakis(triphenylphosphine) palladium (0) (7.4 mg, 0.0064 mmol) was added, the mixture was sparged under nitrogen and then heated at 90° C. for 18 hours. The mixture was cooled to ambient temperature, diluted with ethyl acetate and washed with water and brine. The organic extract was dried with magnesium sulfate, filtered and concentrated in vacuo. The residue was purified by silica gel gradient chromatography (0-55% EtOAc in hexanes), providing the titled compound as a light yellow solid: ¹H-NMR (400 MHz, CDCl₃) δ 8.82 (s, 1H), 8.61 (dd, J=4.9, 1.7 Hz, 1H), 7.87 (dt, J=7.9, 2.0 Hz, 1H), 7.76 (s, 2H), 7.34 (dd, J=7.9, 4.9 Hz, 1H), 4.58 (d, J=7.2 Hz, 2H), 1.41 (m, 1H), 0.66-0.73 (m, 2H), 0.51-0.55 (m, 2H) ppm; LRMS (ES+) m/z 343.1 [(M+H)⁺; calculated for C₁₈H₁₄F₃N₄: 343.2].

The following compounds were prepared according to the general procedure described in Example 33, substituting the appropriate alkyne for (Step 6). The starting materials are either commercially available, known in the literature or may be prepared from commercially available reagents using conventional reactions well known in the art.

Ex. NAME HRMS/LRMS 34

1- (cyclopropylmethyl)- 5-(phenylethynyl)-4- (trifluoromethyl)- 1H-benzotriazole C₁₉H₁₄F₃N₃ Calc'd 342.1 found 342.2 35

1- (cyclopropylmethyl)- 5-(pyridin-4- ylethynyl)-4- (trifluoromethyl)- 1H-benzotriazole C₁₈H₁₃F₃N₄ [M + H] Calc'd 343.1 found 343.2 

What is claimed is:
 1. A compound of Formula I

or a pharmaceutically acceptable salt thereof, wherein: R¹ is selected from the group consisting of: (1) C₂₋₈alkyl, (2) C₂₋₈alkenyl, (3) C₂₋₈alkynyl, (4) C₃₋₆cycloalkyl-(CH₂)_(p)—, wherein p is 1, 2, 3 or 4, and (5) benzyl, wherein groups (1) to (5) above are optionally substituted with 1 to 3 R^(a) groups; each R^(a) and R² is independently selected from the group consisting of: halo, OH, C₁₋₄alkyl, C₁₋₄alkoxy, CF₃, —OCF₃ and —CN; Y is selected from the group consisting of: halo, CN, C₁₋₄alkyl, C₂₋₄alkenyl and CH₃—S(O)_(k)—, wherein said C₁₋₄alkyl and C₂₋₄alkenyl are optionally substituted with hydroxy, oxo and one or more fluoro groups as allowed by valence, and k is 0, 1 or 2; X is selected from the group consisting of: (1) H; (2) C₁₋₈alkyl, C₃₋₈cycloalkyl, C₂₋₈alkenyl or C₂₋₈alkynyl, any of which is optionally substituted with up to 4 substituents selected from R³, said C₃₋₈cycloalkyl further optionally substituted with 1 or 2 oxo groups and said C₁₋₈alkyl further optionally substituted with ═N—OH; (3) phenyl, benzyl, benzoylmethyl, heteroaryl, heteroaryl-CH₂—, heteroaryl-CH₂CH₂— or heteroaryl-CH₂CH₂CH₂—, any of which is optionally substituted with up to 4 substituents selected from R³; (4) Het, Het-CH₂—, Het-CH₂CH₂— or Het-CH₂CH₂CH₂—, any of which is optionally substituted with up to 4 substituents selected from R³, the Het portions thereof further optionally substituted with 1 or 2 oxo groups; each R³ is independently selected from the group consisting of: halogen, OH, CN, CF₃, R⁵, OR⁵, SR⁵, SOR⁵, SO₂R⁵, SO₂N(R⁴)₂, COR⁴, CO₂R⁴, CON(R⁴)₂, CON(R⁴)OR⁵, N(R⁴)₂, NO₂, NR⁴COR⁵, NR⁴CO₂R⁵, NR⁴—C₁₋₄alkyl-CO₂R⁵, —C₁₋₄alkyl-N(R⁴)₂, —C₁₋₄alkyl-NR⁴COR⁵ and —C₁₋₄alkyl-NR⁴CO₂R⁵; each R⁴ independently represents: (1) H, C₁₋₆alkyl, C₂₋₆alkenyl, C₂₋₆alkynyl, C₃₋₁₀cycloalkyl, C₃₋₁₀cycloalkylC₁₋₄alkyl, C₃₋₁₀cycloalkenyl or C₃₋₁₀cycloalkenylC₁₋₄alkyl, any of which except H optionally bear up to 5 halogen atoms or OH, CN, CF₃ and C₁₋₄alkoxy; (2) phenyl, benzyl or heteroaryl, optionally bridged with a methylene, any of which optionally bear up to 3 substituents independently selected from halogen, OH, oxo, CN, CF₃, C₁₋₄alkyl, C₁₋₄hydroxyalkyl, C₃₋₆cycloalkyl, phenyl, heteroaryl, C₁₋₄alkoxy, acetyl, amino, carbamoyl, CO₂—C₁₋₄alkyl, C₁₋₄alkylamino and di(C₁₋₄alkyl)amino; and (3) Het, optionally bridged with a methylene and said Het optionally bearing up to 3 substituents independently selected from halogen, OH, oxo, CN, CF₃, C₁₋₄alkyl, C₁₋₄hydroxyalkyl, C₃₋₆cycloalkyl, phenyl, heteroaryl, C₁₋₄alkoxy, acetyl, amino, carbamoyl, CO₂—C₁₋₄alkyl, C₁₋₄alkylamino and di(C₁₋₄alkyl)amino; or when two R⁴ group are attached to the same nitrogen atom, they may be joined together with said nitrogen atom to form a non-aromatic monocyclic, a non-aromatic or partially aromatic bicyclic or a non-aromatic spiro-linked heterocyclic system of up to 12 ring atoms which optionally bears up to 4 substitutents independently selected from halogen, OH, oxo, CN, CF₃, C₁₋₄alkyl, C₃₋₆cycloalkyl, phenyl, heteroaryl, C₁₋₄alkoxy, acetyl, amino, C₁₋₄alkylamino and di(C₁₋₄alkyl)amino; R⁵ has the same definition as R⁴ except that R⁵ is not H; each “heteroaryl” independently refers to 5- or 6-membered aromatic monocyclic or 9- or 10-membered aromatic bicyclic ring systems, in which at least one ring atom is selected from N or N-oxide, O and S; and each “Het” independently refers to nonaromatic or partially aromatic mono- or bicyclic heterocyclic systems of up to 10 ring atoms, in which at least one ring atom is selected from N, O and S, where the sulfur atom may be in the form of the S-oxide or S,S-dioxide.
 2. The compound according to claim 1, or a pharmaceutically acceptable salt thereof, wherein R² is not present.
 3. The compound according to claim 1, or a pharmaceutically acceptable salt thereof, wherein R¹ is selected from 2,2-dimethylpropyl, 1,2,2-trimethylpropyl, 4,4,4-trifluorobutyl, cyclopropylmethyl and cyclobutylmethyl.
 4. The compound according to claim 3, or a pharmaceutically acceptable salt thereof, wherein R¹ is selected from 2,2-dimethylpropyl and cyclopropylmethyl.
 5. The compound according to claim 1, or a pharmaceutically acceptable salt thereof, wherein X is Het, optionally substituted with up to 4 substituents selected from R³ and further optionally substituted with 1 or 2 oxo groups.
 6. The compound according to claim 5, or a pharmaceutically acceptable salt thereof, wherein X is piperidinyl, optionally substituted with up to 4 substituents selected from R³.
 7. The compound according to claim 1, or a pharmaceutically acceptable salt thereof, wherein X is heteroaryl optionally substituted with up to 4 substituents selected from R³.
 8. The compound according to claim 7, or a pharmaceutically acceptable salt thereof, wherein X is pyridinyl, pyrazinyl or pyridazinyl, each optionally substituted with up to 4 substituents selected from R³.
 9. The compound according to claim 1, or a pharmaceutically acceptable salt thereof, wherein X is C₁₋₆alkyl or C₂₋₆alkenyl, optionally substituted with hydroxy.
 10. The compound according to claim 1, or a pharmaceutically acceptable salt thereof, wherein X is Het, Het-CH₂—, Het-CH₂CH₂— or Het-CH₂CH₂CH₂—, optionally substituted with up to 4 substituents selected from R³, the Het portion thereof further optionally substituted with 1 or 2 oxo groups.
 11. The compound according to claim 10, or a pharmaceutically acceptable salt thereof, wherein X is imidazolidin-2,4-dione-CH₂—, imidazolidin-2,4-dione-CH₂CH₂— or imidazolidin-2,4-dione-CH₂CH₂CH₂—, each optionally substituted with 1 to 2 substituents selected from R³.
 12. The compound according to claim 1, or a pharmaceutically acceptable salt thereof, wherein X is phenyl optionally substituted with up to 4 substituents selected from R³.
 13. The compound according to claim 1, or a pharmaceutically acceptable salt thereof, wherein: R¹ is selected from 2,2-dimethylpropyl and cyclopropylmethyl; R² is not present; Y is Cl, Br or CF₃; X is selected from the group consisting of: (1) piperidinyl, optionally substituted with COR⁴, up to 4 halogen atoms and C₁₋₄ alkyl, optionally bearing up to 5 halogen atoms; (2) pyridinyl, pyrazinyl or pyridazinyl, each optionally substituted with up to 4 substituents selected from halogen, methoxy, N(R⁴)₂, COR⁴, CON(R⁴)₂ and C₁₋₄alkyl, optionally substituted with hydroxy; (3) C₁₋₆alkyl or C₂₋₆alkenyl, optionally substituted with hydroxy; (4) imidazolidin-2,4-dione-CH₂—, imidazolidin-2,4-dione-CH₂CH₂— or imidazolidin-2,4-dione-CH₂CH₂CH₂—, wherein the imidazolidin-2,4-dione portion is optionally substituted with methyl; and (5) phenyl, optionally substituted with up to 4 substituents selected from halogen, methoxy, N(R⁴)₂, COR⁴, CON(R⁴)₂ and C₁₋₄alkyl, optionally substituted with hydroxy.
 14. A compound according to claim 1 selected from the following group:

or a pharmaceutically acceptable salt of any of the foregoing compounds.
 15. A pharmaceutical composition comprising a compound according to claim 1, or a pharmaceutically acceptable salt thereof, in combination with a pharmaceutically acceptable carrier.
 16. A method for treating a neurological or psychiatric disorder associated with glutamate dysfunction in a patient in need thereof comprising administering to the patient a therapeutically effective amount of a compound according to claim 1, or a pharmaceutically acceptable salt thereof.
 17. The method according to claim 16 wherein the neurological or psychiatric disorder associated with glutamate dysfunction is schizophrenia. 